New submission from Jonas H. <jo...@lophus.org>: (This applies to all versions of Python I investigated, although the attached patch is for Python 2.7)
I wondered why `import uuid` took so long, so I did some profiling. It turns out that `find_library` wastes at lot of time because of this crazy regular expression in `_findSoname_ldconfig`. A quick look at the ldconfig source (namely, the print_cache routine which is invoked when you call `ldconfig -p`, http://sourceware.org/git/?p=glibc.git;a=blob;f=elf/cache.c#l127) confirmed my suspicion that the ldconfig's output could easily be parsed without such a regex monster. I attached two patches that fix this problem. Choose one! ;-) The ctypes tests pass with my fixes, and here comes some benchmarking: $ cat benchmark_ctypes.py from ctypes.util import find_library for i in xrange(10): for lib in ['mm', 'c', 'bz2', 'uuid']: find_library(lib) # Current implementation $ time python benchmark_ctypes.py real 0m11.813s ... $ time python -c 'import uuid' real 0m0.625s ... # With my patch applied $ cp /tmp/ctypesutil.py ctypes/util.py $ time python benchmark_ctypes.py real 0m1.785s ... $ time python -c 'import uuid' real 0m0.182s ... ---------- assignee: theller components: ctypes files: faster-find-library1.diff keywords: patch messages: 128910 nosy: jonash, theller priority: normal severity: normal status: open title: ctypes: Speed up find_library() on Linux by 500% type: performance versions: Python 2.5, Python 2.6, Python 2.7, Python 3.1, Python 3.2, Python 3.3 Added file: http://bugs.python.org/file20808/faster-find-library1.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue11258> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
